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Lesson 4 Is this an MVP?
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Introduction to Free Fall A free-falling object is an object that is falling under the sole influence of gravity. Any object that is being acted upon only by the force of gravity is said to be in a state of free fall. There are two important motion characteristics that are true of free-falling objects: ⢠Free-falling objects do not encounter air resistance. ⢠All free-falling objects (on Earth) accelerate downwards at a rate of 9.8 m/s/s (often approximated as 10 m/s/s for back-of-the-envelope calculations) Because free-falling objects are accelerating downwards at a rate of 9.8 m/s/s, a ticker tape trace or dot diagram of its motion would depict an acceleration. The dot diagram at the right depicts the acceleration of a free-falling object. The position of the object at regular time intervals - say, every 0.1 second - is shown. The fact that the distance that the object travels every interval of time is increasing is a sure sign that the ball is speeding up as it falls downward. Recall from an earlier lesson, that if an object travels downward and speeds up, then its acceleration is downward. Free-fall acceleration is often witnessed in a physics classroom by means of an ever-popular strobe light demonstration. The room is darkened and a jug full of water is connected by a tube to a medicine dropper. The dropper drips water and the strobe illuminate the falling droplets at a regular rate - say once every 0.2 seconds. Instead of seeing a stream of water free-falling from the medicine dropper, several consecutive drops with increasing separation distance are seen. The pattern of drops resembles the dot diagram shown in the graphic at the right. The Acceleration of Gravity It was learned in the previous part of this lesson that a free-falling object is an object that is falling under the sole influence of gravity. A free-falling object has an acceleration of 9.8 m/s/s, downward (on Earth). This numerical value for the acceleration of a free-falling object is such an important value that it is given a special name. It is known as the acceleration of gravity - the acceleration for any object moving under the sole influence of gravity. A matter of fact, this quantity known as the acceleration of gravity is such an important quantity that physicists have a special symbol to denote it - the symbol g. The numerical value for the acceleration of gravity is most accurately known as 9.8 m/s2. There are slight variations in this numerical value (to the second decimal place) that are dependent primarily upon on altitude. We will occasionally use the approximated value of 10 m/s2 in order to reduce the complexity of the many mathematical tasks that we will perform with this number. By so doing, we will be able to better focus on the conceptual nature of physics without too much of a sacrifice in numerical accuracy. g = 9.8 m/s2, downward Look It Up! Even on the surface of the Earth, there are local variations in the value of the acceleration of gravity (g). These variations are due to latitude, altitude and the local geological structure of the region. Recall from an earlier lesson that acceleration is the rate at which an object changes its velocity. It is the ratio of velocity change to time between any two points in an object's path. To accelerate at 9.8 m/s2 means to change the velocity by 9.8 m/s each second. If the velocity and time for a free-falling object being dropped from a position of rest were tabulated, then one would note the following pattern. Time (s) Velocity (m/s) 0 0 1 - 9.8 2 - 19.6 3 - 29.4 4 - 39.2 5 - 49.0 . Observe that the velocity-time data above reveal that the object's velocity is changing by 9.8 m/s each consecutive second. That is, the free-falling object has an acceleration of approximately 9.8 m/s2. Another way to represent this acceleration of 9.8 m/s2 is to add numbers to our dot diagram that we saw earlier in this lesson. The velocity of the ball is seen to increase as depicted in the diagram at the right. (NOTE: The diagram is not drawn to scale - in two seconds, the object would drop considerably further than the distance from shoulder to toes.) Representing Free Fall by Graphs ⢠Early in Lesson 1 it was mentioned that there are a variety of means of describing the motion of objects. One such means of describing the motion of objects is through the use of graphs - position versus time and velocity vs. time graphs. In this part of Lesson 5, the motion of a free-falling motion will be represented using these two basic types of graphs. Representing Free Fall by Position-Time Graphs A position versus time graph for a free-falling object is shown below. Observe that the line on the graph curves. As learned earlier, a curved line on a position versus time graph signifies an accelerated motion. Since a free-falling object is undergoing an acceleration (g = 9.8 m/s/s), it would be expected that its position-time graph would be curved. A further look at the position-time graph reveals that the object starts with a small velocity (slow) and finishes with a large velocity (fast). Since the slope of any position vs. time graph is the velocity of the object (as learned in Lesson 3), the small initial slope indicates a small initial velocity and the large final slope indicates a large final velocity. Finally, the negative slope of the line indicates a negative (i.e., downward) velocity. Representing Free Fall by Velocity-Time Graphs A velocity versus time graph for a free-falling object is shown below. Observe that the line on the graph is a straight, diagonal line. As learned earlier, a diagonal line on a velocity versus time graph signifies an accelerated motion. Since a free-falling object is undergoing an acceleration (g = 9,8 m/s/s, downward), it would be expected that its velocity-time graph would be diagonal. A further look at the velocity-time graph reveals that the object starts with a zero velocity (as read from the graph) and finishes with a large, negative velocity; that is, the object is moving in the negative direction and speeding up. An object that is moving in the negative direction and speeding up is said to have a negative acceleration (if necessary, review the vector nature of acceleration). Since the slope of any velocity versus time graph is the acceleration of the object (as learned in Lesson 4), the constant, negative slope indicates a constant, negative acceleration. This analysis of the slope on the graph is consistent with the motion of a free-falling object - an object moving with a constant acceleration of 9.8 m/s/s in the downward direction. The Kinematic Equations The goal of this first unit has been to investigate the variety of means by which the motion of objects can be described. The variety of representations that we have investigated includes verbal representations, pictorial representations, numerical representations, and graphical representations (position-time graphs and velocity-time graphs). In Lesson 6, we will investigate the use of equations to describe and represent the motion of objects. These equations are known as kinematic equations. There are a variety of quantities associated with the motion of objects - displacement (and distance), velocity (and speed), acceleration, and time. Knowledge of each of these quantities provides descriptive information about an object's motion. For example, if a car is known to move with a constant velocity of 22.0 m/s, North for 12.0 seconds for a northward displacement of 264 meters, then the motion of the car is fully described. And if a second car is known to accelerate from a rest position with an eastward acceleration of 3.0 m/s2 for a time of 8.0 seconds, providing a final velocity of 24 m/s, East and an eastward displacement of 96 meters, then the motion of this car is fully described. These two statements provide a complete description of the motion of an object. However, such completeness is not always known. It is often the case that only a few parameters of an object's motion are known, while the rest are unknown. For example as you approach the stoplight, you might know that your car has a velocity of 22 m/s, East and is capable of a skidding acceleration of 8.0 m/s2, West. However you do not know the displacement that your car would experience if you were to slam on your brakes and skid to a stop; and you do not know the time required to skid to a stop. In such an instance as this, the unknown parameters can be determined using physics principles and mathematical equations (the kinematic equations). The BIG 4 The kinematic equations are a set of four equations that can be utilized to predict unknown information about an object's motion if other information is known. The equations can be utilized for any motion that can be described as being either a constant velocity motion (an acceleration of 0 m/s/s) or a constant acceleration motion. They can never be used over any time period during which the acceleration is changing. Each of the kinematic equations include four variables. If the values of three of the four variables are known, then the value of the fourth variable can be calculated. In this manner, the kinematic equations provide a useful means of predicting information about an object's motion if other information is known. For example, if the acceleration value and the initial and final velocity values of a skidding car is known, then the displacement of the car and the time can be predicted using the kinematic equations. Lesson 6 of this unit will focus upon the use of the kinematic equations to predict the numerical values of unknown quantities for an object's motion. The four kinematic equations that describe an object's motion are: There are a variety of symbols used in the above equations. Each symbol has its own specific meaning. The symbol d stands for the displacement of the object. The symbol t stands for the time for which the object moved. The symbol a stands for the acceleration of the object. And the symbol v stands for the velocity of the object; a subscript of i after the v (as in vi) indicates that the velocity value is the initial velocity value and a subscript of f (as in vf) indicates that the velocity value is the final velocity value. Each of these four equations appropriately describes the mathematical relationship between the parameters of an object's motion. As such, they can be used to predict unknown information about an object's motion if other information is known. In the next part of Lesson 6 we will investigate the process of doing this. Kinematic Equations and Problem-Solving The four kinematic equations that describe the mathematical relationship between the parameters that describe an object's motion were introduced in the previous part of Lesson 6. The four kinematic equations are: In the above equations, the symbol d stands for the displacement of the object. The symbol t stands for the time for which the object moved. The symbol a stand for the acceleration of the object. And the symbol v stands for the instantaneous velocity of the object; a subscript of i after the v (as in vi) indicates that the velocity value is the initial velocity value and a subscript of f (as in vf) indicates that the velocity value is the final velocity value. Problem-Solving Strategy In this part of Lesson 6 we will investigate the process of using the equations to determine unknown information about an object's motion. The process involves the use of a problem-solving strategy that will be used throughout the course. The strategy involves the following steps: 1. Construct an informative diagram of the physical situation. 2. Identify and list the given information in variable form. 3. Identify and list the unknown information in variable form. 4. Identify and list the equation that will be used to determine unknown information from known information. 5. Substitute known values into the equation and use appropriate algebraic steps to solve for the unknown information. 6. Check your answer to ensure that it is reasonable and mathematically correct. The use of this problem-solving strategy in the solution of the following problem is modeled in Examples A and B below. Example Problem A . Ima Hurryin is approaching a stoplight moving with a velocity of +30.0 m/s. The light turns yellow, and Ima applies the brakes and skids to a stop. If Ima's acceleration is -8.00 m/s2, then determine the displacement of the car during the skidding process. (Note that the direction of the velocity and the acceleration vectors are denoted by a + and a - sign.) The solution to this problem begins by the construction of an informative diagram of the physical situation. This is shown below. The second step involves the identification and listing of known information in variable form. Note that the vf value can be inferred to be 0 m/s since Ima's car comes to a stop. The initial velocity (vi) of the car is +30.0 m/s since this is the velocity at the beginning of the motion (the skidding motion). And the acceleration (a) of the car is given as - 8.00 m/s2. (Always pay careful attention to the + and - signs for the given quantities.) The next step of the strategy involves the listing of the unknown (or desired) information in variable form. In this case, the problem requests information about the displacement of the car. So d is the unknown quantity. The results of the first three steps are shown in the table below. Diagram: Given: Find: vi = +30.0 m/s vf = 0 m/s a = - 8.00 m/s2 d = ?? The next step of the strategy involves identifying a kinematic equation that would allow you to determine the unknown quantity. There are four kinematic equations to choose from. In general, you will always choose the equation that contains the three known and the one unknown variable. In this specific case, the three known variables and the one unknown variable are vf, vi, a, and d. Thus, you will look for an equation that has these four variables listed in it. An inspection of the four equations above reveals that the equation on the top right contains all four variables. vf2 = vi2 + 2 ⢠a ⢠d Once the equation is identified and written down, the next step of the strategy involves substituting known values into the equation and using proper algebraic steps to solve for the unknown information. This step is shown below. (0 m/s)2 = (30.0 m/s)2 + 2 ⢠(-8.00 m/s2) ⢠d 0 m2/s2 = 900 m2/s2 + (-16.0 m/s2) ⢠d (16.0 m/s2) ⢠d = 900 m2/s2 - 0 m2/s2 (16.0 m/s2)*d = 900 m2/s2 d = (900 m2/s2)/ (16.0 m/s2) d = (900 m2/s2)/ (16.0 m/s2) d = 56.3 m The solution above reveals that the car will skid a distance of 56.3 meters. (Note that this value is rounded to the third digit.) The last step of the problem-solving strategy involves checking the answer to assure that it is both reasonable and accurate. The value seems reasonable enough. It takes a car a considerable distance to skid from 30.0 m/s (approximately 65 mi/hr) to a stop. The calculated distance is approximately one-half a football field, making this a very reasonable skidding distance. Checking for accuracy involves substituting the calculated value back into the equation for displacement and insuring that the left side of the equation is equal to the right side of the equation. Indeed it is! Example Problem B Ben Rushin is waiting at a stoplight. When it finally turns green, Ben accelerated from rest at a rate of a 6.00 m/s2 for a time of 4.10 seconds. Determine the displacement of Ben's car during this time period. Once more, the solution to this problem begins by the construction of an informative diagram of the physical situation. This is shown below. The second step of the strategy involves the identification and listing of known information in variable form. Note that the vi value can be inferred to be 0 m/s since Ben's car is initially at rest. The acceleration (a) of the car is 6.00 m/s2. And the time (t) is given as 4.10 s. The next step of the strategy involves the listing of the unknown (or desired) information in variable form. In this case, the problem requests information about the displacement of the car. So d is the unknown information. The results of the first three steps are shown in the table below. Diagram: Given: Find: vi = 0 m/s t = 4.10 s a = 6.00 m/s2 d = ?? The next step of the strategy involves identifying a kinematic equation that would allow you to determine the unknown quantity. There are four kinematic equations to choose from. Again, you will always search for an equation that contains the three known variables and the one unknown variable. In this specific case, the three known variables and the one unknown variable are t, vi, a, and d. An inspection of the four equations above reveals that the equation on the top left contains all four variables. d = vi ⢠t + ½ ⢠a ⢠t2 Once the equation is identified and written down, the next step of the strategy involves substituting known values into the equation and using proper algebraic steps to solve for the unknown information. This step is shown below. d = (0 m/s) ⢠(4.1 s) + ½ ⢠(6.00 m/s2) ⢠(4.10 s)2 d = (0 m) + ½ ⢠(6.00 m/s2) ⢠(16.81 s2) d = 0 m + 50.43 m d = 50.4 m The solution above reveals that the car will travel a distance of 50.4 meters. (Note that this value is rounded to the third digit.) The last step of the problem-solving strategy involves checking the answer to assure that it is both reasonable and accurate. The value seems reasonable enough. A car with an acceleration of 6.00 m/s/s will reach a speed of approximately 24 m/s (approximately 50 mi/hr) in 4.10 s. The distance over which such a car would be displaced during this time period would be approximately one-half a football field, making this a very reasonable distance. Checking for accuracy involves substituting the calculated value back into the equation for displacement and insuring that the left side of the equation is equal to the right side of the equation. Indeed, it is! The two example problems above illustrate how the kinematic equations can be combined with a simple problem-solving strategy to predict unknown motion parameters for a moving object. Provided that three motion parameters are known, any of the remaining values can be determined. In the next part of Lesson 6, we will see how this strategy can be applied to free fall situations. Or if interested, you can try some practice problems and check your answer against the given solutions. Kinematic Equations and Free Fall As mentioned in Lesson 5, a free-falling object is an object that is falling under the sole influence of gravity. That is to say that any object that is moving and being acted upon only be the force of gravity is said to be "in a state of free fall." Such an object will experience a downward acceleration of 9.8 m/s/s. Whether the object is falling downward or rising upward towards its peak, if it is under the sole influence of gravity, then its acceleration value is 9.8 m/s/s. Like any moving object, the motion of an object in free fall can be described by four kinematic equations. The kinematic equations that describe any object's motion are: The symbols in the above equation have a specific meaning: the symbol d stands for the displacement; the symbol t stands for the time; the symbol a stands for the acceleration of the object; the symbol vi stands for the initial velocity value; and the symbol vf stands for the final velocity. Applying Free Fall Concepts to Problem-Solving There are a few conceptual characteristics of free fall motion that will be of value when using the equations to analyze free fall motion. These concepts are described as follows: ⢠An object in free fall experiences an acceleration of -9.8 m/s/s. (The - sign indicates a downward acceleration.) Whether explicitly stated or not, the value of the acceleration in the kinematic equations is -9.8 m/s/s for any freely falling object. ⢠If an object is merely dropped (as opposed to being thrown) from an elevated height, then the initial velocity of the object is 0 m/s. ⢠If an object is projected upwards in a perfectly vertical direction, then it will slow down as it rises upward. The instant at which it reaches the peak of its trajectory, its velocity is 0 m/s. This value can be used as one of the motion parameters in the kinematic equations; for example, the final velocity (vf) after traveling to the peak would be assigned a value of 0 m/s. ⢠If an object is projected upwards in a perfectly vertical direction, then the velocity at which it is projected is equal in magnitude and opposite in sign to the velocity that it has when it returns to the same height. That is, a ball projected vertically with an upward velocity of +30 m/s will have a downward velocity of -30 m/s when it returns to the same height. These four principles and the four kinematic equations can be combined to solve problems involving the motion of free-falling objects. The two examples below illustrate application of free fall principles to kinematic problem-solving. In each example, the problem solving strategy that was introduced earlier in this lesson will be utilized. Example Problem A Luke Autbeloe drops a pile of roof shingles from the top of a roof located 8.52 meters above the ground. Determine the time required for the shingles to reach the ground. The solution to this problem begins by the construction of an informative diagram of the physical situation. This is shown below. The second step involves the identification and listing of known information in variable form. You might note that in the statement of the problem, there is only one piece of numerical information explicitly stated: 8.52 meters. The displacement (d) of the shingles is -8.52 m. (The - sign indicates that the displacement is downward). The remaining information must be extracted from the problem statement based upon your understanding of the above principles. For example, the vi value can be inferred to be 0 m/s since the shingles are dropped (released from rest; see note above). And the acceleration (a) of the shingles can be inferred to be -9.8 m/s2 since the shingles are free-falling (see note above). (Always pay careful attention to the + and - signs for the given quantities.) The next step of the solution involves the listing of the unknown (or desired) information in variable form. In this case, the problem requests information about the time of fall. So t is the unknown quantity. The results of the first three steps are shown in the table below. Diagram: Given: Find: vi = 0.0 m/s d = -8.52 m a = - 9.8 m/s2 t = ?? The next step involves identifying a kinematic equation that allows you to determine the unknown quantity. There are four kinematic equations to choose from. In general, you will always choose the equation that contains the three known and the one unknown variable. In this specific case, the three known variables and the one unknown variable are d, vi, a, and t. Thus, you will look for an equation that has these four variables listed in it. An inspection of the four equations above reveals that the equation on the top left contains all four variables. d = vi ⢠t + ½ ⢠a ⢠t2 Once the equation is identified and written down, the next step involves substituting known values into the equation and using proper algebraic steps to solve for the unknown information. This step is shown below. -8.52 m = (0 m/s) ⢠(t) + ½ ⢠(-9.8 m/s2) ⢠(t)2 -8.52 m = (0 m) *(t) + (-4.9 m/s2) ⢠(t)2 -8.52 m = (-4.9 m/s2) ⢠(t)2 (-8.52 m)/(-4.9 m/s2) = t2 1.739 s2 = t2 t = 1.32 s The solution above reveals that the shingles will fall for a time of 1.32 seconds before hitting the ground. (Note that this value is rounded to the third digit.) The last step of the problem-solving strategy involves checking the answer to assure that it is both reasonable and accurate. The value seems reasonable enough. The shingles are falling a distance of approximately 10 yards (1 meter is pretty close to 1 yard); it seems that an answer between 1 and 2 seconds would be highly reasonable. The calculated time easily falls within this range of reasonability. Checking for accuracy involves substituting the calculated value back into the equation for time and insuring that the left side of the equation is equal to the right side of the equation. Indeed it is! Example Problem B Rex Things throws his mother's crystal vase vertically upwards with an initial velocity of 26.2 m/s. Determine the height to which the vase will rise above its initial height. Once more, the solution to this problem begins by the construction of an informative diagram of the physical situation. This is shown below. The second step involves the identification and listing of known information in variable form. You might note that in the statement of the problem, there is only one piece of numerical information explicitly stated: 26.2 m/s. The initial velocity (vi) of the vase is +26.2 m/s. (The + sign indicates that the initial velocity is an upwards velocity). The remaining information must be extracted from the problem statement based upon your understanding of the above principles. Note that the vf value can be inferred to be 0 m/s since the final state of the vase is the peak of its trajectory (see note above). The acceleration (a) of the vase is -9.8 m/s2 (see note above). The next step involves the listing of the unknown (or desired) information in variable form. In this case, the problem requests information about the displacement of the vase (the height to which it rises above its starting height). So d is the unknown information. The results of the first three steps are shown in the table below. Diagram: Given: Find: vi = 26.2 m/s vf = 0 m/s a = -9.8 m/s2 d = ?? The next step involves identifying a kinematic equation that would allow you to determine the unknown quantity. There are four kinematic equations to choose from. Again, you will always search for an equation that contains the three known variables and the one unknown variable. In this specific case, the three known variables and the one unknown variable are vi, vf, a, and d. An inspection of the four equations above reveals that the equation on the top right contains all four variables. vf2 = vi2 + 2 ⢠a ⢠d Once the equation is identified and written down, the next step involves substituting known values into the equation and using proper algebraic steps to solve for the unknown information. This step is shown below. (0 m/s)2 = (26.2 m/s)2 + 2 â˘(-9.8m/s2) â˘d 0 m2/s2 = 686.44 m2/s2 + (-19.6 m/s2) â˘d (-19.6 m/s2) ⢠d = 0 m2/s2 -686.44 m2/s2 (-19.6 m/s2) ⢠d = -686.44 m2/s2 d = (-686.44 m2/s2)/ (-19.6 m/s2) d = 35.0 m The solution above reveals that the vase will travel upwards for a displacement of 35.0 meters before reaching its peak. (Note that this value is rounded to the third digit.) The last step of the problem-solving strategy involves checking the answer to assure that it is both reasonable and accurate. The value seems reasonable enough. The vase is thrown with a speed of approximately 50 mi/hr (merely approximate 1 m/s to be equivalent to 2 mi/hr). Such a throw will never make it further than one football field in height (approximately 100 m), yet will surely make it past the 10-yard line (approximately 10 meters). The calculated answer certainly falls within this range of reasonability. Checking for accuracy involves substituting the calculated value back into the equation for displacement and insuring that the left side of the equation is equal to the right side of the equation. Indeed, it is! Kinematic equations provide a useful means of determining the value of an unknown motion parameter if three motion parameters are known. In the case of a free-fall motion, the acceleration is often known. And in many cases, another motion parameter can be inferred through a solid knowledge of some basic kinematic principles.
LESSON 4. Cellular Respiration ⢠Define cellular respiration ⢠Identify the stages of clan respiration You have just learned how the energy from the sun is captured, processed, and stored in the form of glucose. Cellular respiration, another important life process, is the means by which cells release the stored energy in glucose to make adenosine triphosphate (ATP). The primary goal of this life process is to convert stored energy into usable form, such as ATP, for the cells to carry out their functions. Cellular respiration involves several chemical reactions. The reactions can be summed up in the following equation: C6 H12 O6 + 602 -----ď 6 COâ +6HâO + ATP Glucose oxygen carbon dioxide water energy Aerobic respiration reactions, or cellular respiration that takes place in the presence of oxygen, can be grouped into three stages glycolysis, Krebs cycle, and electron transport chain (ETC). Stage 1: Glycolysis Glycolysis is the process that breaks down one molecule of 6-C glucose into 3-C pyruvates or pyruvic acids. It also releases four molecules of ATP. This process occurs in the cytoplasm of the cell. The following is the step-by-step process of glycolysis. Take note that several enzymes are involved in this process. 1. The first step of glycolysis requires energy. It can only proceed when the two ATP molecules donate energy to the glucose by transferring a phosphate group with the help of an enzyme, producing glucose 6-phosphate 2. Then, a specific enzyme promotes the rearrangement of the atoms, producing the fructose 6-phosphate. 3. The action of the enzyme in step 2 promotes the transfer of a phosphate group from another ATP molecule, forming fructose 1,6-bisphosphate. 4. The resulting fructose 1,6-bisphosphate molecules, with the help of another enzyme, splits into two molecules, each with three carbon backbones. These two sugars are dihydroxyacetone phosphate and glyceraldehyde 3-phosphate. 5. Another important enzyme then rapidly interconverts the molecules of dihydro-xyacetone phosphate and glyceraldehyde 3-phosphate. This produces two molecules of glyceraldehyde 3-phosphate or 3-phosphoglyceraldehyde (PGAL) 6. The succeeding step involves another enzyme-mediated action. The hydrogen (H) from PGAL is transferred to the oxidizing agent, nicotinamide adenine dinucleotide (NAD), which forms NADH. A phosphate (P) is also added from the cytosol of the cell to oxidize the two molecules of PGAL, forming two 1.3-bisphosphoglycerate. 7. A phosphate (P) from 1,3-biphosphoglycerate is transferred to ADP to form ATP. This happens for each of the two 1,3-bisphosphoglycerate. resulting to a yield of two ATP and two 3-phosphoglycerate molecules. 8. A phosphate is transferred from 3-phosphoglycerate molecules from the third carbon to the second carbon, forming 2-phosphoglycerate molecules A hydrogen atom and a hydroxyl ((OH) group is released, which then combines to form water (H2O). The removal of H2O from 2-phosphoglycerate results in the formation of 2- phosphoglycerate molecules. 9. A hydrogen atom and a hydroxyl ((OH) group is released, which then combines to form water (H2O). The removal of H2O from 2-phosphoglycerate results in the formation of two phosphoenolpyruvic acid (PEP) 10. Phosphate (P) from PEP is transferred to ADP (and forms ATP) and the final product, pyruvic acid. This reaction yields two molecules of pyruvic acid and two ATP molecules In summary, a single glucose molecule that undergoes the process of glycolysis produces two molecules of pyruvic acid, four molecules of ATP, two molecules of NADEL and two molecules of H.O. However, only two molecules of ATP are counted as net products since two molecules of ATP are spent throughout the process. Stage II: Krebs Cycle The Krebs cycle, named after its proponent Sir Hans Adolf Krebs, is a cyclical series of enzyme-controlled reactions. This stage of cellular respiration occurs in the matrix of the mitochondria. It is sometimes. called the citric acid cycle (CAC) since it produces citric acid. Citric acid contains three carboxyl (COOH) groups; hence, it is also called the tricarboxylic acid cycle (TCA). This requires the pyruvic acids produced during glycolysis. The main function of this cycle is to produce high-energy-yielding molecules, namely, NADH and flavin adenine dinucleotide (FADH) that will later on be used in the electron transport chain reaction. Figure 6-7. Summary of glycolysis and corresponding products in each reaction presented (See Appendix F on page 285 for an enlarged and complete version of the image.) An initial process is needed for the Krebs cycle to begin. As a pyruvate molecule from glycolysis enters the mitochondrion, it undergoes an important preliminary ate to form acetyl-CoA reaction. Coenzyme-A (COA) combines with pyruvate help of an enzymatic complex. This conversion also produces CO, and NADH. The Krebs cycle is summarized as follows. Take note that several enzymes are involved in this process. 1. The Krebs cycle technically begins when the acetyl-CoA combines with oxaloacetic acid (OAA), a 4-C molecule, to produce citric acid, a 6-C molecule. 2. With the aid of an enzyme, the citric acid now goes through a series of reactions that releases energy. Water molecule is removed from the citric acid and is returned in a different location. The-OH group is repositioned, forming the molecule isocitrate. 3. Isocitrate is then oxidized, forming the a-ketoglutarate, a 5-C molecule. The byproducts of this reaction are NADH and CO, 4 The a-ketoglutarate loses its CO, and a coenzyme-A is added in its place. The decarboxylation occurs with the help of NAD, which then becomes NADH. The resulting molecule is called succinyl-CoA. 5. Succinyl-CoA is converted into succinate. Also in this reaction, a molecule of guanosine triphosphate (GTP) is synthesized. The GTP molecule has similar structure and energy properties to that of ATP and is used by cells the same way. The free phosphate group attacks the succinyl-CoA molecule, which detaches the COA. Then, phosphate is attached to GDP to come up with GTP, similar to the process that occur in ATP synthesis (from ADP to ATP). 6. Two hydrogens are removed from succinate, A molecule of flavin adenine dinucleotide (FAD), a coenzyme similar to NAD, is reduced to FADH, as it takes the hydrogens from the succinate. This reaction produces the fumarate. 7. Fumarate is then converted into malate as the addition of a water molecule is catalyzed. The final reaction is the regeneration of oxaloacetate. The resulting byproduct of this regeneration is NADH Recall that two pyruvate molecules were produced during glycolysis, causing the Krebs cycle to turn twice. Each tuts produces three molecules of NADH, single ATH one FADIH, and the by-product CO, which is exhaled. Stage III: Electron Transport Chain The electron transport chain (ETC) is a series of photon pumps on the inner membrane of the mitochondrion. Electron transport is the last stage of the cellular respiration. In this stage, the energy from NADH and FADH, from the Krebs cycle is transferred to ADP to produce ATP. This process is generally known as oxidative phosphorylation. This energy coupling mechanism in the cell was revealed by the work of Peter stored energy in the form of proton (1) gradient to phosphorylate (add phosphate) ADP and produce ATP. The pumping of hydrogen sons across the inner membrane creates higher concentration ions in the inner membrane than on the outside of the membrane. This chemiosmotic gradient causes the ions to flow back across the membrane where the concentration of ions is lower. ATP synthase lined in the matrix serve as a channel protein, helping the ions to move across the membrane. The chemiosmotic gradient powers the phosphorylation of ADP to ATP, which also occurs in the ATP synthase. After passing through the ETC, the oxygen, being the final hydrogen acceptor, combines with two electrons and two protons, forming a water molecule. Water is a by-product of cellular respiration and is excreted. MINI TEST 6-3 1. Which energy-releasing pathway yields the most ATF in each glucose molecule? 2. Briefly describe the two stages of aerobic respiration that follow glycolysis: (a) Krebs cycle (b) Electron transport chain Anaerobic Respiration Most cells carry out arrobic respiration when oxygen is present. Aerobic respiration is an efficient process that yields a lot of ATP. However, many organisms thrive in mud, marshes, animal gut, canned goods, sewage treatment pond, and deep oceans where oxygen is scarce. Organisms that can live without oxygen are called anaerobes. Cellular respiration that proceeds without the presence of oxygen is called anaerobic respiration. In the event that the oxygen supply becomes low, aerobic cells also perform fermentation and lactic acid fermentation anaerobic pathways. There are two common anaerobic pathways in these cells, alcoholic fermentation and lactic acid fermentation. In alcoholic fermentation, ethyl alcohol and carbon dioxide are produced by some cells using the pyruvate from glycolysis. Each pyruvate molecule is rearranged into acetaldehyde and carbon dioxide, which is eventually released. NADII gives up electrons to acetaldehyde to form ethanol Fermentation is widely used in the industry. Yeast, a fungus used in making bread. can undergo anaerobic respiration. Bakers aux sugar, flour, water, and yeast to form the bread dough. The dough rises due to the carbon dioxide and alcohol released by the yeast cells trapped in air bubbles. Beer and wine manufacturers, we yeast to ferment the sugars in wheat and grape juice, forming alcoholic beverages such as beer and wine. In some cells, glycolysis produces two pyruvates, two NADH molecules, and two ATP molecules. Pyruvate itself becomes the final acceptor of the electrons from the NADH that produces the final product: lactate. Oftentimes, this product is called lactic acid. Human skeletal muscles can carry out fermentation when the blood cannot supply the cells with adequate oxygen during strenuous activities. When lactic acid builds up in the muscles, fatigue, burning sensation, and cramps result. Lactic acid will continue to build up until there is adequate supply of oxygen. Lactic acid is then converted back into pyruvate in the liver. Muscles also restore normal functions. Have you ever wondered why milk or cream turns sour after some time? Bacterial cells that undergo fermentation are responsible in producing lactate that turns the milk sour. These bacteria are used in manufacturing yogurt and sour milk products. Fermentation pathways do not breakdown and utilize the glucose completely. ATP is no longer produced beyond the process of glycolysis. Thus, energy produced is just enough for some single-celled organisms, or the energy can only be used by multicellular organisms for a short period.
RPMS Quiz: Quality vs. Efficiency 1. A teacher spends five hours creating a highly interactive digital game for a single 40-minute lesson. This is an example of prioritizing: ⢠A) Quality over Efficiency ⢠B) Efficiency over Quality ⢠C) Administrative Competence ⢠D) Resource Management ⢠Hint: The focus is on high-level engagement, but the time investment is very high. 2. Which of the following best describes "Efficiency" in the context of the RPMS? ⢠A) Submitting all MOVs and reports on or before the deadline with minimal errors. ⢠B) Ensuring 100% of students pass the quarterly examination. ⢠C) Creating the most aesthetically pleasing portfolio in the department. ⢠D) Conducting home visits for every single student in a class of 50. ⢠Hint: Look for the option that emphasizes timeliness and resource use. 3. Using a "template" or a "reusable slide deck" for lesson planning is a strategy to improve: ⢠A) Efficiency ⢠B) Instructional Diversity ⢠C) Subject Matter Mastery ⢠D) Classroom Discipline ⢠Hint: Templates reduce the time spent on repetitive formatting. 4. If a teacher provides detailed, personalized feedback to every student but submits the grades two weeks late, they have achieved: ⢠A) High Quality, Low Efficiency ⢠B) Low Quality, High Efficiency ⢠C) High Quality, High Efficiency ⢠D) Low Quality, Low Efficiency ⢠Hint: The work itself is excellent, but the timing is poor. 5. Which tool improves Efficiency without sacrificing the Quality of assessment data? ⢠A) Automated Google Forms for multiple-choice quizzes. ⢠B) Giving everyone a passing grade to save time on checking. ⢠C) Writing long paragraphs of feedback on 200 paper-based essays. ⢠D) Skipping assessments entirely to finish the syllabus faster. ⢠Hint: Look for a balance where technology handles the "busy work." 6. When discussing Quality in your RPMS portfolio, which "Means of Verification" (MOV) is most appropriate? ⢠A) Sample of student work with constructive teacher comments. ⢠B) A logbook showing you arrived at school at 7:00 AM daily. ⢠C) A certificate for attending a 1-hour webinar. ⢠D) A photo of your organized teacher's cabinet. ⢠Hint: Quality is evidenced by the impact on student learning. 7. The concept of "Doing the right things" (Effectiveness) represents: ⢠A) Quality ⢠B) Efficiency ⢠C) Speed ⢠D) Compliance ⢠Hint: "Doing the right things" is about results; "Doing things right" is about process. 8. How does "Efficiency" help a teacher maintain "Quality" in the long run? ⢠A) It prevents burnout by optimizing workload, leaving energy for creative teaching. ⢠B) It allows the teacher to take more side jobs. ⢠C) It ensures the teacher never has to talk to parents. ⢠D) It proves that the teacher is smarter than their peers. ⢠Hint: Consider the relationship between teacher well-being and performance. 9. If a teacher's RPMS rating for Quality is 5 (Outstanding) but Efficiency is 2 (Fair), what is the most likely reason? ⢠A) The teacher produces excellent work but often misses deadlines. ⢠B) The teacher is very fast but makes many mistakes in their reports. ⢠C) The teacher is both slow and produces poor results. ⢠D) The students are failing despite the teacher being very organized. ⢠Hint: Check the gap between the high-standard output and the slow delivery. 10. What is the ultimate goal of balancing Quality and Efficiency in the PPST-RPMS? ⢠A) To achieve sustainable professional excellence that benefits the learners. ⢠B) To get a higher salary increase only. ⢠C) To impress the School Head during the observation. ⢠D) To finish the school year with the least amount of work possible. ⢠Hint: It's about long-term growth for both teacher and student. ________________________________________ Answer Key: 1. A | 2. A | 3. A | 4. A | 5. A | 6. A | 7. A | 8. A | 9. A | 10. A ________________________________________
GRADE 4 Module 6 Lesson 3. Interpret Remainders This PowerPoint file contains instructional aids for teachers who have purchased Into Math. It is intended to be projected to students and used in conjunction with the Student Edition and manipulatives as needed. These slides can be used to move the conversation forward in the classroom, but they should not serve as a replacement for student-centered, collaborative conversations in which students have the space they need to find an entry point, construct meaning, and build understanding.â â About the Slide Presentationâ Presenter View: Use the Presenter view to see notes while presenting. â Customization: Add or delete content or notes to get the best learning experience for your classroom. 1 Problem of the Day. Which equations can be used to solve the following problem? Rita makes 40 bracelets and gives an equal number to 8 friends, including Veronica. Veronica gives 2 of the bracelets that she received to her sister. How many bracelets does Veronica have left? A. 40 â 8 = 32 32 á 2 = 16 B. 40 á 8 = 5 5 + 2 = 7 C. 8 + 2 = 10 40 á 10 = 4 D. 40 á 8 = 5 5 â 2 = 3 2 I Can. I Can solve a division problem and interpret the remainder in the context of the problem. 3 Spark Your Learning. Aiden is building solar toy cars in his science club. The cars collect and use energy from the sun for power. Aiden buys 18 wheels. Each car needs 4 wheels. How many cars can Aiden build? Show your thinking. 4 Turn and Talk. What is the remainder in this problem? What does the remainder mean? Professional Development note: Use the Professional Learning Cards to provide language routines that may help students access the meaning of the problem. 5 Build Understanding ⢠Task 1 ACTIVITY. There are 57 students going to the science museum. Each van can take 5 students. How many vans are needed to take all the students? Use a visual model to show how the students are divided into groups of 5. 6 Turn and Talk. How can you use the whole-number quotient and remainder to answer these questions? How many vans will be full? How many students will ride in the van that is not full? Professional Development note: Use the Professional Learning Cards to provide language routines that may help students access the meaning of the problem. 7 Step It Out ⢠Task 2 ACTIVITY.. Amanda has 73 inches of wire for a science experiment. She needs to cut all the wire into 8 identical pieces. How many inches long will each piece be? 8 Turn and Talk. Why is this problem a good situation to write the remainder as a fraction? Professional Development note: Use the Professional Learning Cards to provide language routines that may help students access the meaning of the problem. 9 Check Understanding. 1. Maya needs 44 batteries for smoke alarms. The batteries come in packs of 6. How many packs does Maya need to buy? For 44 á 6, the whole-number quotient is ____ and the remainder is ____. Maya needs to buy ____ packs. Circle how you interpreted the remainder to solve the problem. 10 I Can Scale. 4 I can explain how to solve a division problem and interpret the remainder in the context of the problem. 3 I can solve a division problem and interpret the remainder in the context of the problem. 2 I can solve a division problem and identify the whole-number quotient and the remainder. 1 I can solve a division problem with a remainder. 11 Exit Ticket. Mr. Jenkinsâ class is giving speeches during a 46-minute class. Each student will be able to talk for 4 minutes. How many students can give speeches? Justify your answer.
Can you make a multiple choice of test questions regarding this information given which is Curriculum from Different Points of View There are many definitions of curriculum. Because of this, the concept of curriculum is sometimes characterized as fragmentary, elusive and confusing. However, the numerous definitions indicate dynamism that connotes diverse interpretations of what curriculum is all about. The definitions are influenced by models of thought, pedagogies, political as well as cultural experiences. Let us study some of these definitions. 1. Traditional Points of View of Curriculum In early years of the 20th century, the traditional concepts held of the âcurriculum is that it is a body of subjects or subject matter prepaid by the teachers for the studentâs to learnâ. It was synonymous to the âcourse of studyâ and âsyllabusâ Robert M. Hutchins views curriculum as âpermanent studiesâ where the rules of grammar, reading, rhetoric and logic and mathematics for basic education are emphasized. Basic education should emphasize the 3 Rs and college education should be grounded on liberal education. On the other, Arthur Bestor as an essentialist, believes that the mission of the school should be intellectual training, hence curriculum should focus on the fundamental intellectual disciplines of grammar, literature and writing. It should also include mathematics, science, history and foreign language. The definition leads us to the view of Joseph Schwab that discipline is the sole source of curriculum. Thus in our education system, curriculum is divided into chunks of knowledge we call subject areas in basic education such as English, Mathematics, Science, Social Studies and others. In college, discipline may include humanities, sciences, language and many more. To Phoenix, curriculum should consist entirely of knowledge which comes from various disciplines. Academic discipline became the view of what curriculum is after the cold war and the race to space. Joseph Schwab, a leading curriculum theorist coined the term discipline as a ruling doctrine for curriculum development. Curriculum should consist only of knowledge which comes from disciplines which is the sole source. Thus curriculum can be viewed as a field of study. It is made up of its foundations (philosophical, historical, psychological and social foundations); domains of knowledge as well as its research theories and principles. Curriculum is taken as scholarly and theoretical. It is concerned with broad historical, philosophical and social issues and academics. Most of the traditional ideas view curriculum as written documents or a plan of action in accomplishing goals. 2. Progressive Points of View of Curriculum On the other hand, to a progressivist, a listing of school subjects, syllabi, course of study, and a list of courses or specific discipline do not make a curriculum. These can only be called curriculum if the written materials are actualized by the learner. Broadly speaking, curriculum is defined as the total learning experiences of the individual. This definition is anchored on John Deweyâs definition of experience and education. He believed that reflective thinking is a means that unifies curricular elements. Thought is not derived from action but tested by application. Caswell and Campbell viewed curriculum as âall experiences children have under the guidance of teachersâ. This definition is shared by Smith, Stanley and Shores when they defined âcurriculum as a sequence of potential experiences set up in the schools for the purpose of disciplining children and youth in group ways of thinking and actingâ. Marsh and Willis on the other hand view curriculum as all the âexperiences in the classroom which are planned and enacted by the teacher, and also learned by the studentsâ. Points of View on Curriculum Development From the various definitions and concepts presented, it is clear that curriculum is a dynamic process. Development connotes changes which are systematic. A change for the better means any alteration, modification or improvement of existing condition. To produce positive changes, development should be purposeful, planned and progressive. This is how curriculum evolves. Let us look at the two models of curriculum development and concepts of Ralph Tyler and Hilda Taba. Ralph Tyler Model: Four Basic Principles. This is also popularly known as Tylerâs Rationale. He posited four fundamental questions or principles in examining any curriculum in schools. These four fundamental principles are as follows: 1. What educational purposes should the school seek to attain? 2. What educational experiences can be provided that are likely to attain these purposes? 3. How can these educational experiences be effectively organized? 4. How can we determine whether these purposes are being attained or not? In summary, Tylerâs Model show that in curriculum development, the following considerations should be made: (1) Purpose of the school, (2) Educational experiences related to the purposes, (3) Organization of the experiences, and (4) Evaluation of the experiences. On the other hand, Hilda Taba improved on Tylerâs Rationale by making a linear model. She believed that teachers who teach or implement the curriculum should participate in developing it. Her advocacy was commonly called the grassroots approach. She presented seven major steps to her model where teachers could have a major input. These steps are as follows: 1. Diagnosis of learnerâs needs and expectations of the larger society. 2. Formulation of learning objectives. 3. Selection of learning content. 4. Organization of learning content. 5. Selection of learning experiences. 6. Organization of learning activities. 7. Determination of what to evaluate and the means of doing it. Thus as you look into curriculum models, the three interacting processes in curriculum development are planning, implementing and evaluating. Types of Curriculum Operating in Schools From the various concepts given, Allan Glatthorn(2000) describes seven types of curriculum operating in the schools. These are (1) Recommended curriculum- proposed by scholars and professional organizations. (2) Written Curriculum- appears in school, district, division or country documents. (3) Taught Curriculum- what teacherâs implement or deliver in the classrooms and schools. (4) Supported Curriculum- resources-textbooks, computers, audio- visual materials which support and help in the implementation of the curriculum. (5) Assessed Curriculum- that which is tested and evaluated. (6) Learned Curriculum- which the students actually learn and what is measured and (7) Hidden Curriculum- the unintended curriculum. 1. Recommended Curriculum- Most of the school curricula are recommended. The curriculum may come from a national agency like the Department of Education, Commission on Higher Education (CHED), Department of Science and Technology (DOST) or any professional organization who has stake in education. For example the Philippine Association for Teacher Education (PAFTE) or the Biology Teacher Association (BIOTA) may recommend a curriculum to be implemented in the elementary or secondary education. 2. Written Curriculum- This includes documents, course of study or syllabi handed down to the schools, districts, division, departments or colleges for implementation. Most of the written curricula are made by curriculum experts with participation of teachers. These were pilot-tested or tried out in sample schools or population. Example of this is the Basic Education Curriculum (BEC). Another example is the written lesson plan of each classroom teacher made up of objectives and planned activities of the teacher. 3. Taught Curriculum- The different planned activities which are put into action in the classroom compose the taught curriculum. These are varied activities that are implemented in order to arrive at the objectives or purposes of the written curriculum. These are used by the learners with the guidance of teachers. Taught curriculum varies according to the learning styles of students and the teaching styles of teachers. 4. Supported Curriculum- In order to have a successful teaching, other than the teacher, there must be materials which should support or help in the implementation of a written curriculum. These refer to the support curriculum that includes material resources such as textbooks, computers, audio-visual materials, laboratory equipment, playgrounds, zoos and other facilities. Support curriculum should enable each learner to achieve real and lifelong learning. 5. Assessed Curriculum- This refers to a tested or evaluated curriculum. At the duration and end of the teaching episodes, series of evaluations are being done by the teachers to determine the extent of teaching or to tell if the students are progressing. This refers to the assessed curriculum. Assessment tools like pencil-and-paper tests, authentic instruments like portfolio are being utilized. 6. Learned Curriculum- This refers the learning outcomes achieved by the students. Learning outcomes are indicated by the results of the tests and changes in behavior which can either be cognitive, affective or psychomotor. 7. Hidden Curriculum- This is the unintended curriculum which is not deliberately planned but may modify behavior or influenced learning outcomes. There are lots of hidden curricula that transpire in the schools. Peer influence, school environment, physical condition, teacher-learner interaction, mood of the teachers and many other factors made up the hidden curriculum.
LESSON 2 Early Theories on the Origin of Life ⢠Identify the different theories on the origin of life. ⢠Describe each theory and determine their differences What are the characteristics of living things? Before learning about the history of Earth based on geological evidence, early scientists explored the possibilities of how the first life-form existed. There are several theories about the origin of life. Theory of Catastrophism The theory of catastrophism supported by French scientists Georges Cuvier (1769-1832) and Alcide Dessalines d'Orbigny (1802-1857), is said to be a modification of the creation story of the Bible. It states that there have been several living creations from God, each encountered a catastrophe that completely destroyed them. Each new creation consisted of new life-forms, which happen to be different from the previous ones. Theory of Abiogenesis The theory of abiogenesis, or the spontaneous generation theory, states that living things were naturally created from nonliving things such as simple organic compounds. The theory supposes that abiogenesis occurred between 3.8 and 4 Gya. The experiment performed by Stanley Miller in 1953 gave way to many speculations and studies on how life on Earth really began. His research involved a simulation of the possible environment on Earth in the past. He demonstrated how an electric spark (which is a simulation for lightning) when passed through simple organic gases (similar to the early Earth atmosphere), resulted in the formation of amino acids, which are now known as the building blocks of proteins and the components of living tissues. Theory of Biogenesis The theory of biogenesis presented a strong argument against abiogenesis. This theory states that living things come from living things. Experiments of Francesco Redi and Louis Pasteur disproved the thought of spontaneous generation during their time (figure 5-1). Louis Pasteur argued that life comes from preexisting life and not from nonliving material. However, it should be noted that the "abiogenesis" or "spontaneous generation" that he opposed referred to any modern, existing, fully-formed organisms, not the original generation of life. Louis Pasteur's law of biogenesis contradicted the common belief during his time that cattle dung gives rise to flies, or old clothes with rotten food gives rise to mice. The idea of spontaneous generation was popular until near the seventeenth century. Even famous scientists of that period, such as Descartes, Galileo, and Jan Baptista van Helmont, believed in this theory. CIENCE PIONEER Francesco Redi (1626-1697). Francesco Redi is a physician, a naturalist, and a poet. His works challenged the popular theory of spontaneous generation. He disproved the idea that living things may arise from nonliving things. He also worked on toxicology using viper's venom. He discovered and worked on some parasites that caused disease in humans. SCIENCE CAREER Evolutionary Biologist An evolutionary biologist studies the descent of species and the origin of new species of living things. Working as evolutionary biologist means studying and researching species diversity, their interaction with the environment, their adaptation to change, their ancestors, and their possible origins. This career is important in the field of science because it seeks an answer to the questions about how life began on Earth.
LESSON 3 Characteristics of Living Things Learning Objectives ⢠Describe each characteristic of life ⢠Relate each characteristic of life with how first forms of life evolved What sets living things apart from nonliving things? Organisms are equipped with different characteristics that allow them to grow, adapt, survive, and perpetuate. These include the ability to metabolize, respond to stimuli, interact, and reproduce, among others What are the characteristics of life? Try to look at your surroundings and identify the living things that you see. You have probably identified a lot. Many scientists believe that there are more than 10 million kinds of living things that exist on Earth today. But the question is, how can something be considered living? There are certain characteristics that all living things exhibit: the characteristics of life. Living things are made up of cells. They metabolize, grow and develop, respond to stimulus, adapt to their environment, and reproduce. Living Things Are Made up of Cells All living things are made up of cells. Cells are the basic building blocks of all living things. Each cell contains materials that carry out basic life processes such as respiration. In the 1600s, an argument against the theory of spontaneous generation was made. Italian physician and biologist Francesco Redi disproved the theory that all living things come from nonliving things. Cells have different properties and characteristics. The cell theory describes the properties of all cells. There are three tenets of the cell theory: 1. The cell is the basic unit of life. 2. All living things are composed of one or more cells. 3. All cells arise from preexisting cells. The discovery of the cell is largely attributed to Robert Hooke. Upon examining a piece of cork using a microscope that he built, Hooke observed tiny compartments that he called "cells" (from the Latin word cella, meaning "little room"). Matthias Schleiden suggested that all structural parts of plants are made up of cells. In 1839, Theodore Schwann stated that along with plants, all animals were composed of cells. From these conclusions about plants and animals, advancement on the study of animal parts and functions began. In 1855, Rudolf Virchow included the idea that all cells came from preexisting cells. Some living things are made up of only single cells. Single-celled or unicellular organisms include bacteria, some protists, and some fungi. Even though composed of single cells, these organisms carry out all the functions necessary for life. Most living things such as animals and plants, are multicellular organisms. They are composed of many cells, which are grouped together and perform specific tasks in the body. In different organisms, cells also vary in sizes, shapes, parts, and functions. There are two kinds of organisms according to their cell structure, the prokaryotes and eukaryotes (figure 5-3). Prokaryotes are single-celled organisms that lack a membrane-bound nucleus, mitochondria, and all other organelles. Its name comes from the Greek words pro, which means "before," and karyon, which means "nut or kernel." Eukaryotes are organisms with cells that contain membrane-bound nucleus and other membrane-bound organelles. The nucleus of a eukaryotic cell contains the genetic material (DNA), enclosed by a nuclear envelope. Other membrane-bound organelles are mitochondria, Golgi apparatus, and chloroplast found in photosynthetic organisms such as algae and plants. There are also unicellular eukaryotes known as protozoa. All other eukaryotes are multicellular organisms, such as plants, animals, and fungi. Living Things Metabolize Essential chemical reactions in life can be best described as building up (anabolism) and breaking down (catabolism) processes. In anabolism, the substances needed by organisms to grow, store energy, and repair tissues are synthesized. In contrast in catabolism, some complex substances are broken down, releasing the energy stored in their molecules. This happens in food digestion. This chemical building up and breaking down processes are collectively called metabolism. Metabolism, from the Greek word metabole meaning "change," is the sum total of all the life-sustaining chemical reactions in living things. It allows living things to grow, maintain their structures and functions, and respond to stimuli. Living Things Grow and Develop Growth and development are not new concepts to many. In all living things, growth involves the increase in one's size or height. However, growth is not just an increase in physical structure. It also involves complex changes in an organism. Growth and development occur rapidly from younger stages of life to maturity. In humans, animals, and plants, distinct changes brought by growth and development can be dearly identified. Microorganisms such as bacteria also undergo growth and development until they reach their maximum size and maturity. A life span is the average length of time a aving thing can live. Living things have different life spans. Humans have average life spectancy of 60 to 70 years, while some plants, such as the narra trees, can live for more than 100. Living Things Respond to Stimuli All living things respond to stimuli the environment. This responsiveness Increases survivability. Stimulus (plural: uli) is any signal or change in he environment of an organism that produces a response or reaction from that organism. Responses to stimuli depend on an organism's need. Responding to stimuli also maintains homeostasis in living things. Homeostasis is the internal balance of a body system. This balance is needed for the proper function and regulation of the living thing's body. For example, when a person is in a warmer environment, the body sweats, keeping the body maintain a temperature suited for the normal function of the body. Living Things Interact No living thing can live alone. Interaction among organisms is simultaneously happening on Earth. From the smallest microorganisms to the biggest organism, and from the North Pole to the South Pole of Earth, all are connected in one living system. An ecosystem is formed when a community of organisms interacts with another community and with their environment. Many processes and interactions, such as in a feeding relationship, life cycle, and the exchange of gases between plants and animals, occur in the ecosystem. These are some of the important processes needed to maintain life on Earth. Living Things Reproduce The ability of living things to produce offspring of their kind is called reproduction. Reproduction is not an individual organism's need, rather, it is for the species' perpetuation. In some cases, animals become extinct because of their inability to reproduce their kind. Higher forms of plants and animals reproduce through sexual reproduction. Sexual reproduction involves the union of sex cells or gametes-the egg cell from a female organism and the sperm cell from a male organism. This union gives rise to a new individual with characteristics or traits from both parents. Other simple organisms, such as bacteria and plants, can reproduce asexually. These organisms give rise to a new individual from their body. A bacterial cell divided in two through asexual reproduction gives rise to new bacteria, as shown in figure 5-5. A yeast can form buds that later on become separate individual. Plants grow new plants using their stem, leaf, and roots. Both sexual and asexual reproductions have important functions. In both cases, the genetic material (DNA) is passed on from one generation to the next, ensuring the survival of the species on Earth. 1. Bacteria copy their DNA by starting at any point on the circular chromosomes. 2. The two copies of DNA attach to the inside wall of the bacterial cell. 3. The cell starts to divide, forming a new membrane and cell wall. 4. The bacterial cell splits into two separate cells, each with their own DNA. Living Things Adapt and Evolve All living things can adapt to their environment. This adaptation is necessary for rvival. Adaptation depends on the need of an individual. A polar bear, for example, would not be able to survive in an extremely cold environment without its capacity adapt. Adaptation is any response or reaction toward a stimulus that helps in the survival of an organism. A seed-eating bird will eventually eat a worm when there are seeds to be found. This change in food choice is therefore its adapting mechanism. Prolonged adaptation to certain environments may lead to the gradual evolution of the succeeding generations. Evolution is the gradual change in organisms over a long period in response to changing environment. Living Things Are Organized Life on Earth exhibits organization. The atom is the smallest unit of matter, lowed by molecules, which are combinations of atoms. When these molecules are grouped together, they form a cell. The cell is the basic unit of life. In multicellular organisms, such as plants and animals, cells are grouped as tissues to perform specific Functions. Different tissues can be grouped further and form organs. Organs in animals include the heart, brain, and lungs, among others. The organs form organ systems that makes the function of the body more complex and efficient. Organ systems form the whole organism. All living things exhibit organization, whether they are unicellular or multicellular organisms..
The advantage of direct method is that the teacher can control the class and fit in a lot of activity into a short class period. This leaves plenty of opportunities for the students to hone their skills, especially new ones. On the other hand, because the class is centered around the teacher, some students may not receive proper feedback, and creativity is limited. Also, the lesser talented athletes often tend to get lost in the shuffle while the great athletes shine. However, there are now a multitude of various teaching strategies that can be employed in addition to that method. Ex: Announcements, Module/Unit introductions, Descriptions/modeling of assignments and learning activities, Written or video lectures, Demonstration videos, Presentations, Discussions moderated by instructors, Interactive tutorials. Indirect Method The Indirect Teaching Style allows students to be involved in their own learning through experience and other peerâs knowledge. Students can use critical thinking to expand their learning capabilities by seeing what others may be doing correct and adjusting this to their own knowledge. The Indirect approach is the opposite of what the direct style suggests, but they are both strictly related, meaning you canât have one without the other. Direct teaching: The instructor stands in front of the class or group and lectures or advises. Indirect teaching: The instructor assumes a more passive role and guides the student interactions. Movement exploration: Incorporates the use of equipment that involves movement. Movement Exploration The movement exploration class is founded on developing a strong, positive association to physical activity. Classes are aimed at developing movement skills and foundational strength through fun and engaging activities. The activities are age appropriate and include games, challenges, and exploration that positively challenge childrenâs competency while improving their physical capabilities. Skills such as the ability to climb, hold animal shapes, gymnastic style activities, and the introduction to athletic motor skill competencies are the foundations to youth training. This class provides the introduction to strength training to give children the opportunity to learn the skills required to safely and confidently engage in resistance training. Cooperative Skills Cooperative activities teach students to work together for their group's common good. By participating in these activities, students can learn the skills of listening, discussing, thinking as a group, group decision making, and sacrificing individual wants for the common good. There are two primary objectives guiding the teaching of cooperative activities. First, cooperative activities allow students to apply a variety of fundamental motor skills in a unique setting. Students are typically asked to perform motor skills in a specific way, such as âskip in general spaceâ or âbalance on one foot and one elbow.â Cooperative activities ask students to perform different activities such as skip with their hands on the shoulders of someone in front of them, walk with big steps while placing their feet on small spots, or walk across an area blindfolded while someone directs their moves. Due to the uniqueness of such experiences, students often find cooperative activities exciting and motivating. Second, cooperative activities are a wonderful medium for teaching social and emotional learning (SEL). SEL offers students an opportunity to understand and manage their emotions. In addition, such activities offer an opportunity to show empathy for others and develop positive relationships. Cooperative activities demand that all students play a role in completing the task or solving the movement problem. Every student, regardless of ability level, is important and contributes to group goals. 9 traits a PE teacher often needs Here are nine essential traits of an effective PE teacher: 1. Athletic ability Athletic ability is an essential trait for a PE teacher because they're often showing kids how to perform exercises. To demonstrate proper form and encourage the kids to continue their fitness education, it's important they can perform the exercises themselves. Having experience with fitness training can enhance a PE teacher's lesson planning because they're familiar with how each exercise affects a person's body. Athletic ability can also refer to an aptitude for sports and games. PE teachers can instruct students on how to play these games or lead after-school activities involving them, like soccer or basketball. An aptitude for sports and games can help a PE teacher encourage students to participate in the activities during class. If the PE teacher enjoys physical activity, they may make the lessons more enjoyable for the student. 2. Teaching ability A PE teacher is a member of a school faculty, so it's essential they have the teaching ability that allows them to communicate lessons to students. There are various skills involved in teaching, including the technical capabilities associated with each professional's particular field. Learning these skills can help PE teacher plan their lessons effectively and connect with their students, meaning they can encourage students to practice fitness skills in optimal ways for their health. Here are some important teaching skills for PE teachers: Having an engaging classroom presence ďˇ Real-world learning ďˇ Project building ďˇ Lesson planning ďˇ Technology 3. Interpersonal skills PE coaches are part of faculty teams, so working alongside other teachers is an essential part of their job. They often collaborate with a student's general education teacher to address any behavioral issues that arise. They can also team up with other classes to plan activities for students, like field days and special field trips. Communicating with peers can ensure these interactions remain productive and create opportunities for more fulfilling lessons. Teachers can also model emotional skills for their students by displaying positive social interactions. Interpersonal skills can also help PE teachers interact with students and their families. If a student can make a student feel comfortable expressing their needs and preferences, they can often perform physical exercises or play games to the best of their individual capacities. Understanding how to soothe nerves and support students' emotional needs are important examples of interpersonal skills. When interacting with family members, you may use some of these same techniques to communicate effectively and best uplift students. 4. Written and verbal communication Both verbal and written communication is important for PE teachers because they often communicate with students, families and various personnel on a day-to-day basis. For example, a PE teacher uses their communication skills in a lesson plan to describe any student assignments or expectations accurately. They may also write instructions in a document, then explain them in a classroom lecture. They also use communication skills to share their lesson plans with other PE teachers during conferences or classroom development exercises. Many teachers continue to learn their trade even after working as a teacher for many years. They may share tips with each other or special lessons they've developed if they feel another teacher may benefit from it. Creating a community can help PE teachers continue to expand their teaching methodology and receive feedback on their lessons. 5. Patience and adaptability Working with children can require patience and adaptability because they're encountering many new concepts at the same time and learning how to regulate their emotions. As a result, it's important to treat them with patience and care while they're in your class so they can feel comfortable and feel motivated to complete assignments. As children become teenagers, they may require patience and adaptability to account for their changing bodies and attention spans. Like any job where you perform tasks in real-time, certain circumstances may occur that require you to adapt lesson plans. For example, if the weather turns from sunshine to rain on a day you planned for students to run a mile outside, you may need to adapt the lesson plan so they can practice endurance sports inside a gymnasium instead. 6. Organization PE teachers can use organization skills to improve their lesson planning sessions. For example, they can keep their plans in one place, and determine which parts of a semester or quarter to introduce new concepts. Throughout the year, these objectives may change because of unforeseen setbacks, but organizational skills can help PE teachers control the trajectory of their class curriculum. PE teachers can also use organizational skills to maintain their classroom space. Physical education frequently requires balls, equipment and tools to play games that may be on a lesson plan. They also organize equipment and decide where to store it within their classroom or storage space. 7. Creativity Creativity can help a PE teacher develop fun ways to introduce new material to their students or reinforce previous lessons. They can teach new games or devise interesting ideas to change the rules of a game to help keep students engaged. To find inspiration for their lesson plans, they can turn to personal hobbies or media aspects they enjoy, like movie scenes, songs or dances. A varied lesson plan can foster more engagement among students who prefer action- based learning activities, rather than lectures. 8. Focus Focus is an essential trait of a PE teacher because students often require their full attention during class, especially if they're learning a complicated physical task. You can focus your lesson plans around specific elements of physical education you believe are essential for students of a certain age group or skill level. If students require mentorship, you can also focus on each student's needs to supply them with a steady support system. Focusing on your students can help guide your career purpose. It can give you a core value system that informs your lesson plans and mentorship activities. This passion for your student's well-being can also help you become an advocate for each student in your class. You can also help organize funding for different field trips or establish after-school activities to support their interests. 9. Enthusiasm for teaching sports and fitness Enthusiasm is essential for a PE teacher. Many physical education activities require high energy and may suit someone who enjoys teaching them to others. Being an effective PE teacher also requires an enthusiasm for working with kids and making a positive impact on their lives.